So I just got done with my 2nd playthrough (First was on Classic, 2nd was on Assisted so I could easily do the no healing or blood collector and under 4 hours challenges) so I think my opinion is solidified that even though I love it, I definitely feel the 2nd half was a lot weaker than the 1st, it picks back up when you enter the labs, but I'm kinda disappointed they completely drop the whole angle of the zombies sort of vaguely remembering their past and Leon's segment before entering the labs kinda drags and could have used more enemy variety.
Would have liked if they threw in a couple non-zombie enemies in that survived the bombing or escaped/released from the labs for one reason or another, like have Leon run into some Hunters and have to fight those dogs that only appear during the motorcycle segment on foot to spice things up.
Regardless of that, I do think it's better than 7 and 8 were because the 2nd half isn't that bad, it's just that the 1st half just set such a high bar for the rest of the game.